Use DateTimeOffset Instead of Int64/long for Dates

src/Intercom.Tests/Converters/ClassConverters/DateTimeJsonConverterTest.cs

@@ -0,0 +1,117 @@
+using System;
+using System.IO;
+
+using Intercom.Test;
+using Newtonsoft.Json;
+using NUnit.Framework;
+
+using Intercom.Converters.ClassConverters;
+
+namespace Intercom.Tests.Converters.ClassConverters
+{
+    [TestFixture]
+    public class DateTimeOffsetJsonConverterTest : TestBase
+    {
+        private const string _DateCreatedISO = "1989-04-16T00:15:00Z";
+        private const string _DateCreatedUnix = "608688900";
+        private const string _Null = "null";
+
+        private readonly DateTimeOffsetJsonConverter _converter;
+
+        public DateTimeOffsetJsonConverterTest()
+        {
+            _converter = new DateTimeOffsetJsonConverter();
+        }
+
+        [TestCase(_DateCreatedUnix)]
+        public void ReadJson_ForDateTimeOffset_ReturnsValidDateTimeOffset(string json)
+        {
+            using (StringReader stringReader = new StringReader(json))
+            using (JsonReader jsonReader = new JsonTextReader(stringReader))
+            {
+                DateTimeOffset dateCreated = (DateTimeOffset)_converter.ReadJson(jsonReader, typeof(DateTimeOffset), null, null);
+
+                Assert.AreEqual(_ParseUtcDateString(_DateCreatedISO), dateCreated);
+            }
+        }
+
+        [TestCase(_DateCreatedISO)]
+        public void WriteJsonForDateTimeOffset_ForcesUtc(string input)
+        {
+            DateTimeOffset inputDate;
+
+            try
+            {
+                inputDate = _ParseUtcDateString(input);
+            }
+
+            catch (Exception ex)
+            {
+                throw new Exception("Failed to properly parse the test input.", ex);
+            }
+
+            inputDate.ToOffset(TimeSpan.FromHours(-5));
+
+            using (StringWriter stringWriter = new StringWriter())
+            using (JsonWriter jsonWriter = new JsonTextWriter(stringWriter))
+            {
+                _converter.WriteJson(jsonWriter, inputDate, null);
+
+                Assert.AreEqual(_DateCreatedUnix, stringWriter.GetStringBuilder().ToString());
+            }
+        }
+
+        [TestCase(_Null)]
+        public void ReadJson_ForNullableDateTimeOffset_ReturnsNull(string json)
+        {
+            using (StringReader stringReader = new StringReader(json))
+            using (JsonReader jsonReader = new JsonTextReader(stringReader))
+            {
+                DateTimeOffset? dateCreated = (DateTimeOffset?)_converter.ReadJson(jsonReader, typeof(DateTimeOffset?), null, null);
+
+                Assert.AreEqual(null, dateCreated);
+            }
+        }
+
+        [TestCase(null)]
+        public void WriteJsonForNullableDateTimeOffset_ReturnsNull(DateTimeOffset? input)
+        {
+            using (StringWriter stringWriter = new StringWriter())
+            using (JsonWriter jsonWriter = new JsonTextWriter(stringWriter))
+            {
+                _converter.WriteJson(jsonWriter, input, null);
+
+                Assert.AreEqual(_Null, stringWriter.GetStringBuilder().ToString());
+            }
+        }
+
+        [TestCase(_DateCreatedISO)]
+        public void WriteJson_ForDateTimeOffset_ReturnsValidUnixTimestamp(string input)
+        {
+            DateTimeOffset inputDate;
+
+            try
+            {
+                inputDate = _ParseUtcDateString(input);
+            }
+
+            catch (Exception ex)
+            {
+                throw new Exception("Failed to properly parse the test input.", ex);
+            }
+
+            using (StringWriter stringWriter = new StringWriter())
+            using (JsonWriter jsonWriter = new JsonTextWriter(stringWriter))
+            {
+                _converter.WriteJson(jsonWriter, inputDate, null);
+
+                Assert.AreEqual(_DateCreatedUnix, stringWriter.GetStringBuilder().ToString());
+            }
+        }
+
+        private DateTimeOffset _ParseUtcDateString(string input)
+        {
+            return DateTimeOffset.Parse(input);
+        }
+    }
+}

src/Intercom/Clients/UsersClient.cs

@@ -240,36 +240,26 @@ public User Delete(String id)
             return result.Result;
         }
 
-        public User UpdateLastSeenAt(String id, long timestamp)
+        public User UpdateLastSeenAt(String id, DateTimeOffset timestamp)
         {
             if (String.IsNullOrEmpty(id))
             {
                 throw new ArgumentNullException(nameof(id));
             }
 
-            if (timestamp <= 0)
-            {
-                throw new ArgumentException("'timestamp' argument should be bigger than zero.");
-            }
-
             ClientResponse<User> result = null;
             String body = JsonConvert.SerializeObject(new { id = id, last_request_at = timestamp });
             result = Post<User>(body);
             return result.Result;
         }
 
-        public User UpdateLastSeenAt(User user, long timestamp)
+        public User UpdateLastSeenAt(User user, DateTimeOffset timestamp)
         {
             if (user == null)
             {
                 throw new ArgumentNullException(nameof(user));
             }
 
-            if (timestamp <= 0)
-            {
-                throw new ArgumentException("'timestamp' argument should be bigger than zero.");
-            }
-
             String body = String.Empty;
 
             if (!String.IsNullOrEmpty(user.id))

src/Intercom/Converters/ClassConverters/DateTimeJsonConverter.cs

@@ -0,0 +1,65 @@
+using System;
+
+using Newtonsoft.Json;
+
+namespace Intercom.Converters.ClassConverters
+{
+    public class DateTimeOffsetJsonConverter : JsonConverter
+    {
+        public override bool CanConvert(Type objectType)
+        {
+            return (objectType.Equals(typeof(DateTimeOffset)) || objectType.Equals(typeof(DateTimeOffset?)));
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            object value = reader.Value;
+
+            if (value == null)
+            {
+                return null;
+            }
+
+            long unixTimestamp;
+
+            try
+            {
+                unixTimestamp = Convert.ToInt64(value);
+            }
+
+            catch (InvalidCastException ex)
+            {
+                throw new FormatException("Dates must be represented as UNIX timestamps in JSON.", ex);
+            }
+
+            DateTimeOffset unixEpoch = _GetUnixEpoch();
+            DateTimeOffset result = unixEpoch.AddSeconds(unixTimestamp);
+
+            return result;
+        }
+
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            if (value == null)
+            {
+                writer.WriteRawValue("null");
+
+                return;
+            }
+
+            DateTimeOffset unixEpoch = _GetUnixEpoch();
+            DateTimeOffset dateTimeOffset = (DateTimeOffset)value;
+
+            dateTimeOffset = dateTimeOffset.ToOffset(TimeSpan.Zero);
+
+            long unixTimestamp = Convert.ToInt64((dateTimeOffset - unixEpoch).TotalSeconds);
+
+            writer.WriteRawValue(unixTimestamp.ToString());
+        }
+
+        private DateTimeOffset _GetUnixEpoch()
+        {
+            return new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero);
+        }
+    }
+}

src/Intercom/Data/Company.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using Newtonsoft.Json;
 using Intercom.Converters.AttributeConverters;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
@@ -12,10 +13,14 @@ public class Company : Model
         public string name { get; set; }
         public Plan plan { get; set; }
         public string company_id { get; set; }
-        public long? remote_created_at { get; set; }
-        public long? created_at { get; set; }
-        public long? updated_at { get; set; }
-        public long? last_request_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? remote_created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? updated_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? last_request_at { get; set; }
         public int? monthly_spend { get; set; }
         public int? session_count { get; set; }
         public int? user_count { get; set; }

src/Intercom/Data/Conversation.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using Intercom.Clients;
 using Intercom.Converters.AttributeConverters;
+using Intercom.Converters.ClassConverters;
 using Intercom.Core;
 using Intercom.Data;
 using Intercom.Exceptions;
@@ -11,10 +12,14 @@ namespace Intercom.Data
 {
     public class Conversation : Model
     {
-        public long created_at { get; set; }
-        public long updated_at { get; set; }
-        public long? waiting_since { get; set; }
-        public long? snoozed_until { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset updated_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? waiting_since { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? snoozed_until { get; set; }
         public Assignee assignee { get; set; }
         public User user { get; set; }
         public bool open { get; set; }

src/Intercom/Data/ConversationPart.cs

@@ -4,16 +4,21 @@
 using Intercom.Clients;
 using Intercom.Exceptions;
 using System.Collections.Generic;
+using Newtonsoft.Json;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
     public class ConversationPart : Model
     {
         public string part_type { get; set; }
         public string body { get; set; }
-        public long created_at { get; set; }
-        public long updated_at { get; set; }
-        public long notified_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset updated_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset notified_at { get; set; }
         public Assignee assigned_to { get; set; }
         public Author author { get; set; }
         public List<Attachment> attachments { get; set; }

src/Intercom/Data/Event.cs

@@ -6,13 +6,15 @@
 using System.Collections.Generic;
 using Newtonsoft.Json;
 using Intercom.Converters.AttributeConverters;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
 	public class Event : Model
 	{
 		public string event_name { get; set; }
-		public long? created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? created_at { get; set; }
 		public string user_id { get; set; }
 		public string email { get; set; }
 

src/Intercom/Data/Note.cs

@@ -3,12 +3,15 @@
 using Intercom.Data;
 using Intercom.Clients;
 using Intercom.Exceptions;
+using Newtonsoft.Json;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
     public class Note : Model
     {
-        public long? created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? created_at { get; set; }
         public string body { get; set; }
         public Admin author { get; set; }
         public User user { get; set; }

src/Intercom/Data/Segment.cs

@@ -6,15 +6,18 @@
 using Intercom.Clients;
 
 using Intercom.Exceptions;
-
+using Newtonsoft.Json;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
 	public class Segment : Model
 	{
         public string name { get; set; }
-        public long created_at { get; set; }
-        public long updated_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset updated_at { get; set; }
 
 		public Segment ()
 		{

src/Intercom/Data/User.cs

@@ -3,6 +3,7 @@
 using System.Collections.Generic;
 using Newtonsoft.Json;
 using Intercom.Converters.AttributeConverters;
+using Intercom.Converters.ClassConverters;
 
 namespace Intercom.Data
 {
@@ -12,12 +13,16 @@ public class User : Model
 		public string email { get; set; }
 		public string phone { get; set; }
 		public string name { get; set; }
-		public long? updated_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? updated_at { get; set; }
 		public string last_seen_ip { get; set; }
 		public bool? unsubscribed_from_emails { get; set; }
-		public long? last_request_at { get; set; }
-		public long? signed_up_at { get; set; }
-		public long? created_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? last_request_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? signed_up_at { get; set; }
+        [JsonConverter(typeof(DateTimeOffsetJsonConverter))]
+        public DateTimeOffset? created_at { get; set; }
 		public int? session_count { get; set; }
         public bool? new_session { get; set; }
 		public string user_agent_data { get; set; }